Hurricane Harvey churned into Texas, making landfall in the state late Friday night before downgrading to a tropical storm Saturday afternoon.

About 300,000 people were without power Saturday. CoreLogic predicted that the storm could leave $40 billion in damages.

Rainfall that would continue for days could dump more than 40 inches of water and inundate many communities, including dangerously flood-prone Houston, the nation’s fourth-largest city.

Here is what you could do to help the victims of Hurricane Harvey:

Volunteer at shelters

The American Red Cross in Texas has asked people to volunteer. The office announced on Friday that it would be training volunteers at their shelters. The Salvation Army also announced it would be accepting volunteers for their shelters.

Austin Disaster Relief (ADR) said their Hope Family Thrift Store would host a drive Saturday and was accepting donations for new socks, underwear, cleaning supplies, blankets, toiletries and pillows. The foundation said they have enough clothing to provide to the victims.

Donate cash

The Red Cross and Salvation Army have asked for donations as the groups provide water and shelters to the victims of the storm.

"Right now the best thing people can do is donate money," said Katrina Farmer, a director with the American Red Cross. "This is going to be an expensive disaster."

"Diapers are not provided by disaster relief agencies," the Texas Diaper Bank said on Facebook. The agency has asked people to donate diapers to families displaced by the storm.

The South Texas Blood and Tissue Center said they were desperate for blood donations ahead of the storm. The agency specifically asked for O negative and O positive blood. The center asked people in the area to donate.

Republished from FoxNews.com. The Associated Press contributed to this report.